A Swansea University historian hopes to discover more about an ancient discipline which may have provided "the GPS system" of its day, 500 years ago.

Dr Adam Mosley will study cosmography, a subject believed to combine geography, history and astronomy.

He will also try to find out how it died out in around the 17th Century.

The lecturer wants to discover more about its study and how strong its links were with the seafarers' art of navigating by the stars.

The subject became popular around 500 years ago but died out and part of Dr Mosley's work will be to find out why.

He is undertaking a two month fellowship at Cambridge University to find out more

Historians believe that cosmography as a discipline originated as the result of a mistake in translating texts recovered from the ancient world.

It is first used in a translation of a text by the mathematician, geographer and astronomer Claudius Ptolemy, in a description of the world as it was known to the ancient Greeks and Romans.

"We are not sure why cosmography died or even to what extent it ever really existed as a subject," said Dr Mosley, who specialises in the history of early modern science.

You can argue that the Global Positioning Systems (GPS) in use today are a modern form of cosmography as they combine geography and astronomy to give users precise locations

Dr Adam Mosley

"In the 16th Century, cosmography was commonly represented as a subject that comprised geography, astronomy and history, but at some point that changed and scholars preferred to refer to the individual subjects as distinct disciplines in their own right."

Dr Mosley will be trying to find out the extent to which it was pursued within the universities of Europe.

He wants to establish whether it was part of a practical activity taught to and studied by sailors looking to navigate by the stars.

"You can argue that the Global Positioning Systems (GPS) in use today are a modern form of cosmography as they combine geography and astronomy to give users precise locations," said the doctor.

Cosmography is a term also associated with the Flemish cartographer, Mercator, who published his own atlas that included corrected versions of the maps first produced by Ptolemy.

He also gave his name to the standard way in which world maps were represented (the Mercator projection).

John Dee, Queen Elizabeth I's astrologer, who claimed Welsh descent, also wrote texts on mathematics that offered definition of the subject of cosmography.

Dr Mosley said: "It may be misleading to describe John Dee as a cosmographer, but he is a part of the subject's history and I hope that my research in Cambridge will answer a few questions about the role he played in the development of the discipline."